The run time can be mentioned mathematically as,
$T(n) = \sum_{i=0}^{n-1}\sum_{j=0}^{i^2-1}\sum_{k=0}^{j-1}c$
i.e
$T(n) =c \sum_{i=0}^{n-1}\sum_{j=0}^{i^2-1}j$
$T(n) =c \sum_{i=0}^{n-1}\frac{(i^2-1)(i^2)}{2}$
$T(n) =c \sum_{i=0}^{n-1}(i^4 - i^2)$
considering the higher order term
$T(n) =O(c \sum_{i=0}^{n-1}(i^4) )$
$T(n) =O(n^5)$